Circuit breaker



May 9, 1939. -J. B. M NEILL 2,157,714

CIRCUIT B REAKER Filed Feb. 20, 1937 3 Sheets-Sheet 2 J. B. M NElLL CIRCUIT BREAKER May 9, 1939.

Filed Feb. 20, 1937 3 Sheets-Sheet 3 LIEU! INVENTORS John 5. Mac/Veil].

ATTORNEY Patented May 9, 1939 UNITED STATES PATENT OFFICE CIRCUIT BREAKER Pennsylvania Application February 20, 1937, Serial No. 126,898

15 Claims. (Cl. 200-50) This invention relates to circuit breakers and more particularly to operating mechanisms therefor. The conservation of space generally in connection with the design of electrical apparatus, has, of late, been given more and more attention. Particular efforts to eil'ect economy in space have been made in the design of circuit breakers adapted for the protection of relatively low voltage electrical networks. It is the usual practice in underground network systems to mount the low voltage circuit breakers or network protectors as they are commonly called, in a waterproof housing, which, in turn, are usually located in a manhole or underground vault. It is therefore readily apparent that in installations of this kind, the conservation of space is greatly to be desired. However, in carrying out this desideratum, there has resulted a circuit breaker, which, although compact in design, is impractical due to the difliculty experienced in servicing the contact structure.

The main object therefore of my invention is to provide a circuit breaker, the contact structure and operating mechanism of which are compact in design, but which are readily accessible for inspection and repair.

A further object of my invention is to provide a circuit breaker in which the operating mechanism is separable as a unit from the contact structure so as to render both the contacts and the operating mechanism accessible for inspection, without necessitating the disassembly of these parts.

A further and more specific object of my invention is to provide a circuit breaker in which the operating mechanism for the contact structure is mounted upon a hinged frame so as to be movable as a unit from an operative position in front of the contact structure to an inoperative position remote from the contact structure.

A still further object of the invention is to provide a swinging frame for mounting the operating mechanism of a circuit breaker as a unit, which frame also provides a highly accessible support for relays, auxiliary switches and other accessories necessary for the control and operation of the circuit breaker.

Other objects and advantages relate to details of the circuit breaker structure, and will appear more fully in the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a perspective view of the circuit breaker of my invention, showing the hingedlymounted operating mechanism in the open or inoperative position.

Fig. 2 is a front elevation view of the moving contact assemblage oi the circuit interrupter of my invention.

Fig. 3 is a side elevation view, partially in cross section, showing the principal parts of the contact structure and the operating mechanism, and

Fig. 4 is a front elevation view of the operating mechanism, showing the panel carried by the. hinged frame and the several auxiliary devices mounted thereon.

With particular reference to the drawings, the numeral l designates a base or panel of insulating material upon which the contact assemblage and frame units of the breaker structure are mounted. The fixed contacts for each of the three poles I2, l3 and H are secured to three main current carrying busses l5 mounted in spaced relation upon the insulating panel Ill. The fixed contact and bus arrangement for one of the three poles is shown in Fig. 3. Each pole includes two of the contacts indicated at l2 spaced horizontally and one contact I3 positioned intermediate the contacts l2 but displaced vertically above the line joining the contacts l2. The contacts I are positioned in vertical alinement with the contacts l3. The movable contact arrangement shown more clearly in Figs. 2 and 3 comprises contacts l6, l1 and i8 adapted for respective cooperating engagement with the contacts l2, l3 and H. The movable contacts l6, I1 and I8 are respectively mounted upon contact carrying members I9, 20 and 2|. Each of the contact carrying members I9 and 20 are connected by means of a laminated flexible conductor 23 to a fixed bus 25 mounted upon the insulating panel I0. The bus 25 for each pole is provided with a current transformer 21, which, in turn, provides the necessary current for controlling the circuit breaker operation.

The movable contact structure for the three poles of the breaker is supported upon a contact arm 29 (Fig. 3) pivoted at iii to a suitable support 33 secured to the panel M. The upper portion of the contact arm 29 is provided with a C- shaped recess 35 which cooperates with a clamping member 36 for engaging two horizontally extending parallel bars 31. The clamping members 36 and the bars 31 are maintained in rigid engagement with the contact arm 29 by means of bolts 39. For the two outer poles adjacent the central pole the clamping members 30 cooperate with suitable clamping members ll having the same general configuration as the upper or head portion of the contact arm 29. In order to insulate the clamping members 39 and H of the various poles from each other, the support bars 91 are preferably covered with insulating material 49.

The contact carrying members I9 are pivotally connected at 45 to an eye-bolt 46, which, in turn, passes through the clamping members H of the two outer poles and the head portion of the contact arm 29 of the central pole. A coil spring 41, encircling the eye-bolt 46, positioned between the current carrying member I9 and the clamping member 4I biases the contact arm 29 away from the contact carrying members I9 and is limited in its biasing movement by adjusting nuts 49 secured tothe end of the eye-bolts 45.

The centrally positioned contact carrying member 20 for each pole is pivotally coupled at 49 to an eye-bolt 52, and in turn biased from the clamping members H for the two outer poles and the head portion 53 of the contact arm 29 for the central pole, by springs 55. Movement produced by the biasing action of the spring 55 is limited by the adjusting nuts 56 secured to the end of the eye-bolts 52. It is thus seenthatthecontactmembers I9 and 20 are permitted to move relative to the contact arm 29 and due to the spring engagement between these contact carrying members and the contact arm 29, an equalization of the contact pressure between the fixed contacts I2, I3 and the cooperating moving contacts I9, I1 is obtained.

Each of the clamping members 36 is provided with a pair of spaced downwardly projecting fingers 58 to which are pivotally supported, by means of rods 59, the bifurcated end of contact support members 2 I; The contact supporting member 2| is also biased from the clamping members H for the two outer poles and from the head portion 53 of the central pole, bycoil springs 6|, which, in each instance, are larger in diameter than biasing springs 55 and encircle the same.

The contact arm 29, in addition to the biasing action caused by the springs 41, 55 and 9|, is also .biased to the open circuit position by two accelerating springs 53, the upper ends of which are connected to thearm 29 and the lower ends secured to the bracket 33, as more clearly shown in Figs. 1 and 2.

During the opening operation of the contact structure, contacts I2 and I5 are first to separate, and are followed by contacts I3 and I1. The final break is obtained at the arcing contacts I4 and I9 from which contacts the arc is transferred by magnetic means to an arc extinguishergenerally designated at 54.

The operating mechanism for moving the contact arm 29 to closed position is supported by a framework 1I (Fig. 1) having an upper hinge member 13 and a lower hinge member 14 adapted to be hinged, respectively, to corresponding hinge members 15 and 15 of the bracket 11 mounted upon the panel I0. The side of the frame 1I opposite the hinge members 13 and 14 is provided with a boss 19, having an aperture therethrough,

for the reception of a stud bolt 19. The boss 19 is adapted to engage the boss 9| secured to a suitable bracket 92, also supported from the panel I0. The boss 8i has a threaded aperture 99 for the reception of the stud bolt 19 whereby the frame H is held in the secured or operative position with respect to the contact arm 29.

The operating mechanism supported within the suitable projections 91 of the frame II. The

upper ends of the actuating arms 99 are coupled to one end of a pair of toggle links 99 (Fig. 3) by means of shaft 99. The shaft 99 carries a roller 9i disposed between the toggle links 99, which roller is adapted to engage a bearing plate 92 mounted upon the face of the contact arm 29. The other end of the toggle links 99 is pivotally connected to one end of a second pair of toggle links 93 by the shaft 94. The other end of the pair of toggle links 99 is pivotally connected by a shaft 99 to a single linkage member 91 pivoted at 99 to the frame II.

The linkage members 99, 99 and 91 provide a three-link toggle mechanism which, when in the made or closed position, is retained in that position by a positive latching mechanism comprising a latch member IOI pivoted to the frame H at I02 and having a U-shaped notch I99 for holding the latch roller I04, which, in turn, is iournaled to the link member 91 at I05. The latch member IN is held in the closed position by means of a latch toggle comprising a pair of toggle links I99 and I01 joined at I09 and having the link I99 pivoted to the latch member IOI at I99 and the link I01 pivoted to the frame "at Ill.

The knee of the toggle linkage I99, I91 is adapted to rest in its over-center or made position against a stop II I of the trip lever II2 which is also pivotally mounted to the frame H by the shaft I I0. The trip lever I I2 has abearing surface I I3 against which the operating plunger II4 of a shunt trip I I5 is adapted to strike for the purpose of rocking the trip lever I I2 about its pivot III to break the toggle I09 and I01.

After each tripping operation, the latch member IM and the toggle I09, I01 are reset by means of spring II1 joining the latch member "I and the toggle I01. The spring H1 is anchored at its respective ends in a position so that it moves the toggle I06, I01 to its over-center made position and the latch member IM to its latching position, but does not bias the latch beyond the normal latching position. when the latching member IN is in the latching position, and locked due to the latching toggle I09, I01, and the actuating linkage 99, 99, 91 is in the made or closed position, the pivotal points 94 and 99 are over-center with respect to the line joining the pivotal points 99 and 99. Inasmuch as the knee of the toggle formed by the links 99 and 99 have a bearing surface against the frame H at 99, and since the linkage member 91 is held in the latched position by the latching member I0 I, the force exerted by the contact springs 41, 55 and H through the contact arm 29 bearing against the roller 9| will tend to cause the latching linkage member 91 to rotate in a clockwise direction. The tendency for member 91 to rotate is opposed by the bearing surface I I9 of the latch member III engaging the latching roller I04.

The point of contact of the latching roller I94 with the surface I I9 is such that there is a small moment am about the pivotal axis I92 of the latch arm Hi. This moment arm tends to produce rotation of the arm' I9I in the counterclockwise direction, but when in the latched position is resisted by the toggle I09, I01. Thus,

the trip lever II2, rocking it about its pivot III inthe clockwise directim,causingthe bearing surface III thereof to engage the knee oi the toggle I33, I31 and to move this toggle to the broken position. Breaking the toggle I06,. I01 rotates the latching member III about its pivotal axis I02, thereby releasing the latch roller I03, which, inturn, permits the link 31 to rotate in a clockwise direction about its pivotal axis 36, so

' that the pivot 33 is carried upwardly and to the right, thereby causing the pivotal axis 34 between the linkage 33. 33 to be displaced downwardly with respect to the line'joining the axis 33 and 35. As soon asthe linkage member 31 begins its clockwise rotation, the actuating arm 35 is rocked to the right in a clockwise direction, permitting movement of the contact arm 23 towards the open position. This movement is accelerated by the almost simultaneous operation of the ,itoggle linkage '03, 33. As soon as the linkage 03, 33 is broken and the tripping force is removed from the trip lever I I2 the spring I I1 immediately restores the latch toggle I06, I01 and the linkage member 31 to their normal or set positions. More specifically, the resetting of the link member 31 is accomplished by the curved surface I2I oi the latch member "I engaging the latching roller I03 and causing the linkage member 31 to be rotated in a counter-clockwise direction until the latching roller drops it to the U-shaped notch I03.

In order to reclose the breaker, two agencies are provided, In the event the automatic operation is to be desired, I have provided a driving motor I mounted upon the lower portion of the frame H and coupled through a worm and worm gear enclosed in a casing generally shown at I21, to a crank arm I23 secured to the shaft I23. The end of crank arm I23 is provided with a closing roller I30, which is adapted to engage an arcuate notch I3I of an actuating arm I33, the upper end of which has pivotal engagement with the shaft 34 joining the toggle links 33 and 33. The lower end of the actuating link I33 is provided with a guide stud I35 adapted, for engagement in a curved guide slot I35 positioned in guide plate I36 secured to the side of gear casing I21.

When the contact arm 23 is in the open circuit position and the toggle linkage 33, 33 is in the broken position, the actuating link I33 will be in its lowermost position, so that the guide stud I" will be adjacent the lower end of the guide slot I35. It will be apparent that as the crank arm I23 is rotated in a counter-clockwise direction, the closing roller I33 will engage the arcuate notch I3I and carry the actuating link I33 upwardly so as to move the toggle linkage to the made position, thereby causing roller 3I to engage the bearing plate 32 of the contact arm 23 and move the latter to the closed circuit position. When the toggle linkage 33, 33 is moved to the made position, the link members 33 engage an operating rod I, which, in turn, engages a lever I of a cut-oi! switch I32 connected in the control circuit of the motor I25. Thus, when the toggle linkage 33, 32 is in the made position, switch I42 is thrown to the 01! position, thereby cutting oiI the-supply of current to the operating motor I25.

The notch I3I of the actuating link I33 is so disposed with respect to the closing roller I30 that, upon the toggle linkage 33, 33 reaching its made position, the roller I33 continues its path of movement and becomes disengaged from the notch I3I. In order to prevent undue motion of 7 motoramidrivingmechanimatterthepowerhas been cut oil. by means of the snap switch I42, the motor I25 may be provided with a break mechanism indicated at I45, which may be of a centrifugal orother suitable type.

Manual means for closing the breaker are also provided and comprise a shaft I journaled in brackets 11 and I5I supported by the panel I0. The shaft I50 has a crank arm I53 secured thereto, which arm is provided with a roller I55 which roller is adapted to engage the arcuate end I56 of the manually operable actuating link I51, the upper end of which is journaled to the shaft 36 coupling the toggle linkage 68, 33. The actuating link I51 is biased to the roller engaging position by a spring I50.

The outer end of the manually operated shaft I50 is provided with a male clutch member I60 adapted to be engaged by a suitable female clutch member forming part of an operating handle whereby the shaft I50 may be rocked in a. counter-clockwise direction to move the toggle linkage 08, 33 to the made'position. The crank arm I53 is also provided with a projection I62 which is adapted to be moved into engagement with one end of an auxiliary trip lever I63. Theauxiliary trip lever I63 is shown pivoted at I64 and has its opposite end terminating in a bearing surface I65 which forms a stop for the bearing surface II3 of the trip lever II2. An adjusting screw I66, carried by the bracket I61, provides an adjustable stop surface for adjusting the position of the auxiliary trip lever I63 and the main trip lever II2.

In order to prevent opening the hinged frame 1|, or, in other words, from swinging the operating mechanism to the inoperative position, at times when the breaker contacts are in the closed position, an interlock between the trip mechanism and the securing means for holding the frame H in the fixed position is provided. This interlock consists of a covering member I10 pivoted at I1I to the boss 8I and having a transverse portion I12 normally extending in covering relation across the head of the stud 13 which retains the frame H in the closed position. The covering member I10 is connected by an actuating member I13 to a crank I14 secured to the manual operating shaft I50. The crank I14 is so positioned upon the shaft I50 with respect to the crank I53 that the covering member I10 operate the manual control lever to the-tripped position causing the arm I62 to engage the auxiliary trip lever I63 which, in turn, actuates the main trip lever II2 to cause the braker contacts to be tripped to the open position in a manner previously described.

After the breaker has been tripped in the manner just described by rotating the shaft I53 in a clockwise direction, the stud 13 may be removed and the frame H, and the operating mechanism supported thereby, may be swung to the open position, thus permitting ready access to the contact mechanism for inspection or repair.

As more particularly shown in Fig. 4, the frame H is provided with a panel I80 which is adapted to be rigidly secured to the frame and to be movable therewith. Upon the panel I80 may be mounted suitable relays as generally indicated at I3I, I02 and I83 for the control of the various switching operations. The panel I30 may also be utilized for mounting auxiliary control switches indicated generally at I". The switches I" in this instance may be actuated by an operating rod I" connected to'a bell crank I91 pivoted at I99, which, in turn, is connected by an actuating member I99 to the actuating arm 85. It will be apparent that when the actuating arm II is moved to the open circuit position, connecting member I99 will rock bell crank I91 in a clockwise direction about its pivot I99, causing the actuating member I99 to actuate the switches I99. The actuating member I96 may also be coupled by a suitable link I9I to a semaphore I92 pivoted to the supporting panel III! at I99. The semaphore I92 may have colored windows I94 of different colors adapted to be moved, respectively, in front of an indicating lamp I95. Thus the lamp in projecting light through the colored windows I94, will indicate the open and closed position of the breaker in accordance with a predetermined color code.

It will be understood from the foregoing that although I have shown and described a particular breaker structure embodying a specific contact arrangement, and have shown and described a particular operating mechanism whereby the braker contacts are moved to open and closed position, it is to be understood that the details of construction are for illustrative purposes only, and that other contact and operating mechanisms may be adapted to be arranged for relative movement with the operating mechanism as a whole, without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. A circuit breaker comprising a fixed contact, a contact arm, a movable contact carried by said contact arm and adapted to be moved thereby into and out of contacting engagement with said fixed contact, a frame mounted for swinging movement about a fixed pivot, and operating mechanism supported upon said frame for operating said contact arm to open and closed positions, said operating mechanism including a toggle linkage movable to made and broken positions to respectively move said contact arm to closed and open positions, and latching means for releasably retaining the toggle linkage in the made position, releasable means for securing said frame in a fixed position to render said operating mechanism operative with respect to said contact arm, and movable means interlocked with said latching means for preventing the release of said securing means when the contact arm is in the closed position.

2. A circuit breaker comprising relatively movable contact means, electric operating means for said contact means, a support means for said operating means movable to position said operating means in complete operative engagement with said contact means and to position said operating means away from said contact means.

3. A circuit breaker comprising a support, relatively movable contact means mounted on said support, said contact means being biased to open circuit position, a frame relatively movable with respect to said support, a complete operating mechanism carried by said frame including anoperating member mounted for operating movement in a single plane for operating said contact fi'ieans, said frame being movable to position said operating mechanism with its operating member in complete operative driving relation to said contact means, and to position said operating means and operating member away from said contact means.

4. A circuit breaker comprising a support, relatively movable contact means mounted on said support, said contact means being biased to open circuit position, an electric operating mechanism including an operating member mounted for operating movement in a single plane for operating said contact means, a frame for supporting said operating mechanism pivotally mounted on said support for swinging movement to position said operating mechanism with its operating member in operative driving relation to said contact means and to position said operating mechanism and operating member away from said contact means.

5. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, and operating mechanism carried by said frame, including an operating toggle linkage for operating said contact means, said frame being movable to position said operating mechanism in operative driving relation to said contact means and to position said operating mechanism away from said contact means.

6. A circuit breaker comprising a support, relatively movable contact means mounted on said support, said contact means being biased to open circuit position, a frame relatively movable with respect to said support, a complete operating mechanism for said contact means carried by said frame, said frame being movable to an operative position in which said operating mechanism is disposed in complete operative driving relation to said contact means and in which access to said contact means is prevented, and movable to an inoperative position in which said frame and operating mechanism are away from said contact means to permit access to said contact means.

'7. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, operating mechanism carried by said frame for operating said contact means including electric means for operating said mechanism, said frame being movable to a position in which said operating mechanism is disposed in complete operative driving relation to said contact means, and to a position in which the frame and operating mechanism are away from said contact means.

8. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, a complete operating mechanism carried by said frame for operating said contact means including a tripping means operable in response to predetermined conditions to cause said mechanism to open said contact means, said frame being movable to a position in which said operating mechanism is disposed in operative driving relation to said contact means and to a position in which the frame and operating mech-' anism are away from said contact means.

9. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, operating mechanism carried by said frame including means operable to close said contact means and tripping means operable to cause said mechanism to effect opening of said contact means irrespective of the position of said closing means, said frame being movable to an operative position in which said operating mechanism is disposed in complete operative relation to said contact means, and to a position in which the frame and operating mechanism are away from said contact means.

10. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, operating mechanism carried by said frame including trip means operable to cause said mechanism to open said contact means, said frame being movable to an operative position in which said operating mechanism is disposed in complete operative relation with said contact means, and to an inoperative position in which the frame and mechanism are away from said contact means, and means operable to prevent movement of said frame away from its operative position when said contact means are in closed circuit position.

11. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, operating mechanism carried by said frame including trip means operable to cause said mechanism to open said contact means, said frame being movable to an operative position in which said operating mechanism is disposed in operative relation with said contact means, and to an inoperative position in which the frame and mechanism are away from said contact means, and movable means interlocked with said mechanism operable to prevent movement of said frame away from its operative po- 3: sition when said contact means are in closed circuit position.

12. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, operating mechanism carried by said frame including trip means operable to cause said mechanism to open said contact means, said framebeing movable to an operative position in which said operating mechanism is disposed in operative relation with .said' contact means, and to an inoperative position in which the frame and mechanism are away from said contact means, and means interlocked'with said trip means operable to prevent movement of said frame away from its operative position when said contact means are in closed circuit position.

13. A circuit breaker comprising a support,

.relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, operating mechanism car ried by said frame for operating said contact means including tripping means operable in response to predetermined conditions to cause said operating mechanism to open said contact means, said frame being movable to an operative position in which said operating mechanism is disposed in operative relation to said contact means and to an inoperative position in which the frame and operating mechanism are away from said contact means, means releasably securing said frame in operative position, and movable means interlocked with said operating mechanism for preventing release of said securing means when said contact means are in closed circuit position.

14. A circuit breaker comprising a support, relatively movable contact means mounted on said support, a frame relatively movable with respect to said support, operating mechanism carried by said frame for operating said contact means, said frame being movable to an operative position in which said operating mechanism is disposed in operative relation to said contact means and to an inoperative position in which the frame and operating mechanism are away from said contact means, releasable means for securing said frame in operative position, trip means operable to cause said operating mechanism to effect opening of said contact means, and movable means interlocked with said trip means for preventing release of said securing means when said contact means are in closed circuit position.

15. A circuit breaker comprising a support, relatively movable contacts mounted on said support, a switch member movable to open and to close said contacts, said switch member being biased to open said contacts, a frame movable relative to said support, operating mechanism for said switch member carried by said frame, said mechanism including an actuating member separably engageable with said switch member and movable to open and to closed position by said mechanism to cause opening and closing of said contacts, said frame being movable to a position in which said actuating member and mechanism are disposed in complete operative engagement with said switch member and to a position in which said actuating member and mechanism are away from said contact means and switch member.

JOHN B. MACNEILL. 

